Routing signaling data and media data of a session originated by a terminal in a serving or visited communication network to a terminating side may be significantly improved by additionally providing a session anchor node in the visited communication network. In particular, signaling and media data of the session may be routed directly via the session anchor in the visited communication network to the terminating side, and routing the session back to an internet protocol based home communication network of the terminal may be omitted.
A terminal may camp on a circuit switched access of the visited communication network of the above mentioned communication architecture, and may attach to a control node controlling the circuit switched access. For example, the terminal may camp on an UMTS Terrestrial Radio Access Network (UTRAN) or GSM EDGE Radio Access Network (GERAN) radio access network and may attach to a Mobile Switching Center Server (MSC-S) controlling the UTRAN or GERAN radio access network. Further, the terminal may roam between the circuit switched access and a packet switched access or a session of the terminal may be handed over between the circuit switched access and the packet switched access. In the above mentioned example, the terminal may roam or a session of the terminal be handed over between an Evolved UTRAN (E-UTRAN) or Long Term Evolution (LTE) radio access network to the UTRAN access network.
In all cases, the control node has to be informed of the address information of the session anchor node in the visited communication network for routing a session via the session anchor node of the serving communication network. In addition, when roaming or a session handover being executed, the responsible session anchor node in the visited communication network may be different depending on the type of used access. This necessity for being informed of the address information of the session anchor node in the visited communication network may be even enhanced if session voice continuity of a voice session of the terminal may be requested during a session handover between the packet switched access and the circuit switched access.